/*
自己选择的路 ,跪着也要走完。朋友们 , 虽然这个世界日益浮躁起来,只
要能够为了当时纯粹的梦想和感动坚持努力下去 , 不管其它人怎么样,我
们也能够保持自己的本色走下去。
To the world , you will be a person , but to a person , you
will be the world .                               ——AKPower
*/
//作者:AKPower
//算法:
#include <iostream>
#include <cmath>
#include <algorithm>
#include <cstring>
#include <vector>
#include <map>
#include <queue>
#include <cstdio>
#include <string>
#include <stack>
#include <set>
#define IOS ios::sync_with_stdio(false), cin.tie(0)
using namespace std;
typedef long long ll;
const ll maxn = 310;
const ll INF = 0x3f3f3f3f;
ll a[maxn][maxn];
ll n;
ll ans;
bool vis[maxn];
void dfs(ll now, ll cnt)
{
    if (cnt >= ans)
        return;
    ll del = 0;
    for (ll j = 1; j <= n; j++)
    {
        if (a[now][j] == 0)
            continue;
        if (vis[j])
        {
            del++;
            continue;
        }
        if (j == n)
        {
            ans = min(ans, del + cnt);
            return;
        }
        vis[now] = true;
        dfs(j, cnt + del);
        vis[now] = false;
        del++;
    }
    return;
}

int main()
{
    IOS;
    cin >> n;
    ans = INF;
    for (ll i = 1; i <= n; i++)
    {
        for (ll j = 1; j <= n; j++)
        {
            cin >> a[i][j];
        }
    }
    dfs(1, 0);
    cout << ans << endl;
    getchar();
    getchar();
    return 0;
}
